Ryan DiesemThe Ryan Report

New Portable Oxygen Concentrators:

An Overview of Inova Labs’ Activox 4L and Respironics’ SimplyGo Mini

Compared to previous years, 2015 was a slower year in terms of new home oxygen delivery products hitting the market.

On the portable oxygen concentrator (POC) side, Inova Labs introduced their LifeChoice Activox 4L alongside their new DUO2 home stationary concentrator. These two units can be integrated together, as the DUO2 contains a cradle to hold the Activox 4L (or the original LifeChoice Activox) while the user is at home. The DUO2 has a connector plug that can be coupled to the POC so that the internal POC battery will charge while sitting in the cradle, and there is an extra charging plug for external battery charging as well.

DUO2 home stationary concentratorLifeChoice Activox 4L

Despite a similar size and weight compared to POCs like the Inogen One G3 and Invacare XPO2, oxygen production on the Activox 4L is limited to slightly less than 500 mL per minute which is over 300 mL less than that produced by those same comparative units. Always remember that, as a general rule of thumb, the smaller a POC unit is the less the amount of oxygen that can be produced by the device. In other words, smaller and lighter does not guarantee the POC can produce enough oxygen to meet your oxygen needs.

LifeChoice Activox 4LLike previous Inova Labs POCs, the Activox 4L is an intermittent flow (pulse only) POC that utilizes a minute volume delivery method to deliver oxygen doses – so the faster one breathes at their selected pulse setting on the device, the less oxygen per breath the user receives. Anyone using this device may need to increase the pulse setting when breathing notably faster (such as when up and active) to help maintain oxygenation. Pulse settings on the Activox 4L range from 1 to 4, which is one additional setting over previous Inova Labs models. However, for those that have used previous Inova Labs

POCs – the original LifeChoice or the non-4L version of the LifeChoice Activox – it should be noted that the pulse settings between the devices are not equivalent; in other words, a 1/2/3 setting on the older models will deliver slightly more oxygen volume than the 1/2/3 setting on the Activox 4L. That said, the Activox 4L’s maximum 4 setting will deliver slightly more volume than the older device’s maximum 3 setting.

The Activox 4L does come shipped with a wide variety of portability configurations. The outer bag and straps can be converted into four different carrying styles – over the shoulder, around the waist, briefcase, and backpack – which may appeal to those who do a variety of activities while away from the home and need a versatile option for carrying the device. The battery is internal to the device, so there is no ability to swap batteries when depleted, but there are optional external batteries available for purchase.

SimplyGo Mini

Another POC introduced this year is the SimplyGo Mini by Philips Respironics. The SimplyGo Mini is as described, a smaller version of the company’s SimplyGo. The trade off is the SimplyGo Mini is smaller and lighter but delivers a smaller bolus of oxygen and does not have continuous flow. The SimplyGo Mini is designed in part to compete with similar POCs in the 5 to 6 pound class including the Inogen One G3, the AirSep FreeStyle 5, and Inova Labs’ LifeChoice Activox models. With the discontinuation of Respironics’ EverGo POC a couple of years ago, the SimplyGo Mini may also be considered that unit’s spiritual successor with a smaller size, sleeker design, and easier portability.

SimplyGo MiniDesign aesthetics of the Mini are similar to its larger SimplyGo counterpart, and if you are familiar with the old EverGo POC, the SimplyGo Mini produces about the same amount of oxygen as the EverGo did, which was around 1000 mL per minute. There are some other differences from Respironics’ previous POCs, as well, as the SimplyGo Mini features pulse settings that range from 1 to 5 (earlier units have pulse settings up to 6), plus the ability to use either a single or double battery option – similar to the Inogen One G2/G3 single and double battery configurations available on those devices.

The SimplyGo Mini is an intermittent flow (pulse only) POC with no continuous flow option. Like all Respironics POCs to date, the unit features a hybrid of fixed pulse and minute volume delivery methods. At all settings, when the user’s breathing rate does not exceed the unit’s production capacity at those settings, the SimplyGo Mini will deliver a fixed pulse of oxygen. However, when the user’s rate exceeds the production capacity, the unit will switch to a minute volume delivery method.

Warning: Math Ahead!

For example, the production specification at the 2 setting is a maximum of 440 mL/ min, and the fixed pulse specification is 22 mL of oxygen delivered per breath/pulse. At 15 breaths per minute (15 BPM) and 22 mL delivered per breath, production is 15 BPM x 22 mL = 330 mL/min so the unit can deliver its full pulse volume at this rate. But at 30 BPM and a 440 mL/min maximum production capacity at setting 2, the pulse volume per breath will automatically be reduced to about 15 mL (440 mL / 30 BPM = 14.7 mL per breath). As mentioned, this hybrid delivery method is an approach adopted by all Respironics POCs, and is meant to reduce variability in the oxygen delivered at a given setting over a range of rates while also helping to prevent exceeding the production capacity of the device.

The control panel of the SimplyGo Mini is a simple touch screen, similar to smartphones, set on the top face of the device where pressing on the screen initiates pulse setting selection and other user features. Like most small-form POCs, the unit comes with AC and DC power supplies, storage bag, and soft outer case. The user can have the device shipped with a “standard” or an “extended” battery, where the extended battery has twice the amount of operating time but does add about a pound to the weight of the unit. There are only two carrying options – briefcase style by the top handle or over-the-shoulder via an attached strap.

One Important Note

The SimplyGo Mini is currently not approved for flight travel, though it is likely only a matter of time. Always check with the air carrier prior to any travel to be certain any POC you may be using is approved for use on their flights.

Check the following website link to see the latest list of FAA-approved POCs: https://www.faa.gov/about/initiatives/cabin_safety/portable_oxygen/

Happy Holidays to everyone!image102-1


Inova Labs LifeChoice Activox 4L


Respironics SimplyGo Mini

Production Capacity 480 mL/min (0.48 LPM) 1000 mL/min (1.0 LPM)
Settings 1 / 2 / 3 / 4 1 / 2 / 3 / 4 / 5
Pulse Volumes (per breath) 15 BPM 30 BPM 15 BPM 30 BPM
Setting 1 8 mL 4 mL 11 mL 7 mL
Setting 2 16 mL 8 mL 22 mL 15 mL
Setting 3 24 mL 12 mL 33 mL 22 mL
Setting 4 32 mL 16 mL 44 mL 29 mL
Setting 5 n/a n/a 55 mL 33 mL
Weight (w/single batt.) 4.8 lbs. 5 lbs.
Dimensions (w/single batt.) 7.9″H x 9.1″W x 4.4″D 9.4″H x 8.3″W x 3.6″D
Battery Operating Time Internal External Standard Extended
Setting 2 @ 20 BPM Up to 8.25 hrs. Up to 3.75 hrs. Up to 4 hrs. Up to 8 hrs.
Battery Charge Time Internal External Standard Extended
Up to 4 hrs. Up to 2 hrs. Up to 4 hrs. Up to 8 hrs.
Maximum Altitude 10,000 feet 10,000 feet